A new radio ad that launched this week tells Utahns that the state’s constitution was ratified 122 years ago with an important system of checks and balances among the executive, legislative and judicial branches of government.

And part of that system, the ad emphasizes, is that the state’s part-time Legislature can meet outside its regular 45-day schedule only if called into special session by the Utah governor.

“That balance is now being threatened by a group of legislators seeking to rewrite the Utah Constitution to grant new powers of governance to themselves,” says a man’s voice in the advertisement.

The amendment, sponsored by Rep. Brad Wilson, R-Kaysville, earned unanimous support in the House and a 24-4 vote in the Senate earlier this year.

A spokeswoman for Wilson did not immediately respond to a request for comment Tuesday, but the lawmaker — expected to run for and likely win the position of House speaker — penned an argument in favor of the amendment for the state’s voter information materials with Sen. Dan Hemmert, R-Orem.

“Constitutional Amendment C enables the voice of the people to speak for them any time there is a critical need — not just during the 45 days of the annual general session,” the lawmakers wrote. “Those instances will be rare, but the residents of Utah should not be deprived of their voice when there is an immediate need for action.”

Carpenter said his opposition efforts are not intended as a criticism of the Legislature’s current membership, noting that Wilson is his representative in the House. But a constitutional amendment has more permanence than a change in state statute, he said, and the effects of Constitutional Amendment C will likely outlive the men and women who currently serve in the House and Senate.

“I don’t know who is going to fill those positions 20 years from now,” Carpenter said. “It’s about what happens if my crazy neighbor down the street actually does decide to run and wins.”